HSBC Holdings Plc has instructed about 6,000 employees of its global markets division to cease buying single-name securities on their personal accounts, according to people with knowledge of the matter.

Purchases of single-name stocks, bonds and concentrated exchange-traded funds will be prohibited, Global Head of Markets Thibaut de Roux told staff in an email on Friday, said the people, who asked not to be identified discussing internal communications. The changes also apply to employees managing the lender’s own balance sheet, the people said.

A London-based spokesman for the bank declined to comment.

Employees will be allowed to maintain existing holdings of securities prohibited by the new rules, while any sales must be pre-approved by compliance personnel, staff were told. Managers have been instructed to be vigilant in such approvals and decline requests if necessary, the people said.

HSBC wouldn’t be the first big bank to toughen a policy addressing conflicts of interest. Goldman Sachs Group Inc. barred investment bankers from trading individual stocks and bonds in 2014. By contrast JPMorgan Chase & Co. allows traders to deal for their personal gain through approved brokers. It bans “speculative and other short-term investment activity” or purchasing the securities of a client, according to a 2016 rule book. A spokesman declined to comment.